My experience: I had a series 0 Stainless steel 38MM. It was lovely, but the case got scratched very easily after a few months. The screen, even though it was Sapphire, got a small scratch on it (probably from accidental contact from my diamond anniversary band). When the series 2 came out, I bought the aluminum one, and I like it much better. The resale on the series 0 was terrible. The aluminum case still looks like new. It does have some small screen scratches, particularly around the edge on the top, but I think that is inevitable on a watch with my lifestyle. It is also lighter and more comfortable. I like the sport much better. I pair it with the Milanese band from my series 0 and it looks and feels really good.